Teleconference terminal apparatus, teleconference system, and teleconference method

ABSTRACT

The present invention provides a teleconference terminal apparatus for carrying out a teleconference by transmitting/receiving image and voice signals via a communications network. The teleconference terminal apparatus comprises: an image-capturing device which generates an image signal by capturing an image; an image processing section which converts the image signal to a signal mode corresponding to the communications network and outputs the converted signal; a microphone which performs detection of a voice along with the image capturing, and thereby generates a voice signal corresponding to the level of the voice; a voice processing section which converts the voice signal to a signal mode corresponding to the communications network and outputs the converted signal; and a computing section which increases or reduces the amount of data of the image signal outputted from the image processing section, on the basis of the level of the voice signal.

RELATED APPLICATIONS

This application claims the priority of Japanese Patent Application No.2005-267037 filed on Sep. 14, 2005, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a teleconference terminal apparatus,teleconference system, and teleconference method for carrying out ateleconference using a communications line.

2. Description of the Prior Art

Conventionally, as a teleconference system for carrying out ateleconference among a plurality of points, there has been proposed aconfiguration comprising a plurality of mobile units capable oftransmitting voice signals and image signals, a parent station connectedto these mobile units via a communications network, an imagetransmission device provided in the parent station and capable ofidentifying a voice signal and switching between motion and stillimages, and a plurality of monitors connected to the image transmissiondevice and capable of displaying images of all the mobile units.

In the above configuration, still images of conditions of all of themobile units are displayed on the monitors. Then, image signals obtainedby each mobile unit recording a motion image are transmitted along withvoice signals to the image transmission device of the parent station,and a mobile unit in-use is identified by the image transmission deviceon the basis of the voice signals from each mobile unit, whereby only animage projected on the monitor corresponding to the mobile unit in-useis switched from a still to a motion image. Accordingly, still images ofthe conditions of all of the mobile units can be monitored and a motionimage of the mobile unit in-use can be displayed on the monitor withoutselecting operation particularly on the parent station side (JapaneseUnexamined Patent Publication No. H5-153585).

However, in the teleconference system described in the above publicationdocument, since all of the mobile units transmit image signals of motionimages to the parent station regardless of whether the mobile units arein use, the traffic of the communications network between the mobileunits and the parent station easily expands excessively, thus theproblem is that the amount of data of the image signals should bereduced although the quality of the motion images deteriorates.

SUMMARY OF THE INVENTION

An object of the present invention therefore is to provide ateleconference terminal apparatus, teleconference system, andteleconference method capable of checking contents of particularimportance, through good image quality and the like, while preventingthe traffic in the communications network from expanding.

The present invention is a teleconference terminal apparatus forcarrying out a teleconference by transmitting and receiving an imagesignal and voice signal via a communications network, the teleconferenceterminal apparatus comprising: an image-capturing device which generatesan image signal by capturing an image; an image output processingsection which converts the image signal to a signal mode correspondingto the communications network and which outputs the converted signal; amicrophone which performs detection of a voice along with the imagecapturing, and thereby generates a voice signal corresponding to levelof the voice; a voice output processing section which converts the voicesignal to a signal mode corresponding to the communications network andoutputs the converted signal; and an image output processing controlsection which increases or reduces the amount of data of the imagesignal outputted from the image output processing section, on a basis ofthe level of the voice signal.

Further, the present invention may be configured such that the imageoutput processing section comprises an image codec section whichcompresses the image signal, and the image output processing controlsection increases or reduces the data amount by changing the compressionratio of the image signal in the image codec section.

Moreover, the present invention may be configured such that the imageoutput processing control section is connected to at least an encodersection of the image codec section and a transmission frame memory ofthe voice output processing section, which loads a voice signaltransmitted from the transmission frame memory, and which transmits, tothe encoder section, a command signal associated with increase orreduction of the data amount of the image signal, on a basis of levelinformation of the loaded voice signal.

In addition, the present invention may be configured such that the imageoutput processing control section determines whether the levelinformation of the loaded voice signal, which is inputted, is apredetermined value or more, and wherein the command signal istransmitted to the encoder section such that, if the level informationis at least the predetermined value as a result of the determination,the image signal is obtained as low-compression ratio data, and, if thelevel information is less than the predetermined value as a result ofthe determination, the image signal is obtained as high-compressionratio data.

Further, the present invention may be configured such that in a case inwhich the level information is less than the predetermined value as aresult of the determination, when a current image is set so that thelow-compression ratio data are obtained, the determination is repeateduntil a predetermined time period elapses, and as a result the commandsignal is transmitted to the encoder section so that the image signal isobtained as high-compression ratio data, on the condition that it isstill determined that the level information is less than thepredetermined value.

Furthermore, the present invention may be configured such that the imageoutput processing section comprises a gate which stops transmission ofimage signals, and the image output processing control section increasesor reduces the data amount by stopping transmission of image signals inthe gate at fixed intervals.

The teleconference system of the present invention comprises: aplurality of the teleconference terminal apparatuses having theconfiguration described above; and a communications network whichconnects the teleconference terminal apparatuses to communicate data.

The present invention is a teleconference communication method forcarrying out a teleconference by transmitting and receiving an imagesignal and voice signal via a communications network, wherein when animage signal generated by capturing an image is converted to a signalmode corresponding to the communications network and outputted, theamount of data of the image signal is increased or reduced on the basisof the level of a voice which is generated by detecting voice when theimage capturing is performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of a teleconference system according to anembodiment;

FIG. 2 is an explanatory diagram of a display screen of a teleconferenceterminal apparatus;

FIG. 3 is a flowchart showing a communication image processing routine;and

FIG. 4 is a schematic drawing of the teleconference system according tothe embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention is described hereinafter withreference to FIG. 1 through FIG. 4.

(Teleconference System)

The teleconference system according to the present embodiment has, asshown in FIG. 1, a communications network 2 such as a public line andprivate line, a teleconference terminal apparatus 1, which is describedlater, for carrying out a teleconference by transmitting and receivingan image signal and a voice signal via the communications network 2, aMCU 3 (Multipoint Control Unit) which controls multipoint connectionsamong the teleconference terminal apparatuses 1 within thecommunications network 2, and a groupware server 4 which manages theteleconference terminal apparatuses 1 for users and the like. It shouldbe noted that the teleconference terminal apparatus 1, MCU 3, andgroupware server 4 are configured from commercially availableworkstations, personal computers (PC), network connection devices, andthe like. The functions contained in the teleconference terminalapparatuses 1 and the like are realized by the hardware such as theworkstations, PCs, network connection devices and the like, and softwareprocessing using these hardware resources.

The MCU 3 is configured such as to combine/distribute videos/voices bysimultaneously connecting three or more points to switch or mix thevideos and voices, and thereby realizes a teleconference. Specifically,the MCU 3 is configured so as to be able to perform setting of usedresources for each conference, and setting of a communication rate,audio rate, video rate, video session, the number of split screens,video protocol, participant setting information consisting of the typeof the interface type, connection type, IP address, telephone number,signal port, the number of line channels, and voice level (volume) of aparticipant, the time and date for starting to reserve a conference, andduration time information.

Furthermore, the groupware server 4 is connected to the teleconferenceterminal apparatuses 1 and other terminal apparatus having a groupwareclient function, and has a database required for performingcollaboration work in a group of users by using these teleconferenceterminal apparatuses 1, and a database server which manages thedatabase. Moreover, the groupware server 4 has a conference reservationfunction for performing notification of a conference via an email to aparticipant in the conference, a schedule management function formanaging a schedule, and other functions.

(Teleconference Terminal Apparatus 1)

The teleconference terminal apparatus 1, which is used in theteleconference system configured as described above, has animage-capturing device 11 which generates an image signal by capturingan image of a subject such as a person or the like, a display device 12such as a liquid crystal display device which displays the image signalon a screen, and an image processing section 13 which is connected tothe image-capturing device 11 and the display device 12.

The image processing section 13 has an image transmission conversionfunction which converts an image signal sent from the image-capturingdevice 11 to a signal mode corresponding to the communications network2, and an image reception conversion function which converts an imagesignal sent from the communications network 2 to a signal modecorresponding to the display device 12. The image transmissionconversion function is realized by an A/D converter 21 which convertsthe image signal sent from the image-capturing device 11 to a digitalsignal, a transmission frame memory 22 which stores the image signaldigitalized by the A/D converter 21, an encoder section 24 of an imagecodec section 23, and the like. Moreover, the image reception conversionfunction is realized by a decoder section 25 of the image codec section23, a reception frame memory 27 which stores an image signal outputtedfrom the decoder section 25, a D/A converter 26 which converts the imagesignal to an analog signal, and the like.

The encoder section 24 of the image codec section 23 is provided with animage codec which converts uncompressed image data to a form of acompressed file. Furthermore, the encoder section 24 is capable ofchanging a compression process between two stages of high compressionratio and low compression ratio. The encoder section 24 is capable ofswitching between high compression ratio and low compression ratio suchthat when inputting a voice detection signal from a computing section 51which is described hereinafter, data is compressed at a low compressionratio, and in a case other than when inputting a voice detection signal,data is compressed at a high compression ratio. Further, the decodersection 25 of the image codec section 23 comprises an image codec whichreturns the compressed file of the image data to an uncompressed file.It should be noted that the image codec does not perform losslesscompression in which a compressed file can be completely returned to theoriginal file when the compressed file is decoded (unpacked), butperforms lossy compression for processing the file to the extent thatthe quality of the original file is not damaged.

Moreover, the teleconference terminal apparatus 1 further comprises, asshown in FIG. 2 as well, a microphone 14 which performs detection of avoice along with image capturing performed by the image-capturing device11, and thereby generates a voice signal corresponding to the level ofthe voice, a speaker 15 which outputs the voice signal as a voice, and avoice processing section 16 which is connected to the microphone 14 andthe speaker 15.

The voice processing section 16 has a voice transmission conversionfunction which converts a voice signal sent from the microphone 14 to asignal mode corresponding to the communications network 2, and a voicereception conversion function which converts a voice signal sent fromthe communications network 2 to a signal mode corresponding to thespeaker 15. The voice transmission conversion function is realized by anA/D converter 31 which converts the voice signal sent from themicrophone 14 to a digital signal, a transmission frame memory 32 whichstores the voice signal digitalized by the A/D converter 31, an encodersection 34 of a voice codec section 33, and the like. Further, the voicereception conversion function is realized by a decoder section 35 of thevoice codec section 33, a reception frame memory 37 which stores a voicesignal outputted from the decoder section 35, a D/A converter 36 whichconverts the voice signal to an analog signal, and the like.

As with the image codec section 23, the voice codec section 33 has avoice codec which converts uncompressed data to a form of a compressedfile in the encoder section 34 and decodes (unpacks) the compressed fileto an uncompressed file in the decoder section 35.

The image processing section 13 and the voice processing section 16 areconnected to an interface section 54. The interface section 54 isconnected to the communications network 2. The teleconference terminalapparatus 1 can perform data communication with other teleconferenceterminal apparatus 1, MCU 3, or groupware server 4 via thecommunications network 2.

The interface section 54 is connected to the computing section 51 via alow-speed data processing section 53 which processes control data andthe like. The computing section 51 is connected to the low-speed dataprocessing section 53, the encoder section 24 of the image codec section23, and the transmission frame memory 32 of the voice processing section16, and is capable of transmitting a voice detection signal to theencoder section 24 and reading a voice signal from the transmissionframe memory 32.

The computing section 51 comprises a CPU (central processing unit),memory, and the like, and controls an operation of the teleconferenceterminal apparatus 1. Specifically, by, for example, executing thecommunication image processing routine shown in FIG. 3, when convertingan image signal generated by image-capturing to a signal modecorresponding to the communications network 2 and outputting theconverted signal, the amount of data of the image signal is increased orreduced on the basis of the level of a voice which is generated bydetecting voice when image-capturing is performed. Accordingly, contentsof particular importance can be checked, through good image quality andthe like, while preventing the traffic in the communications network 2from expanding. In other words, the computing section 51 stores data sothat the communication image processing routine, which increases orreduces the amount of data of an image signal on the basis of the levelof a voice generated by detecting voice when image-capturing isperformed, can be executed such that the contents of particularimportance can be checked, through good image quality and the like,while preventing the traffic in the communications network 2 fromexpanding.

Moreover, an operation section 52 such as a keyboard or mouse, and auser information processing section 17 are connected to the computingsection 51. The user information processing section 17 is provided witha web browser function 41, a groupware client function 42, mailtransmission/reception function 43, and the like. Accordingly, theteleconference terminal apparatus 1 can view a web page present on theInternet, by means of the web browser function 41, and also can transmitor receive mails to and from other teleconference terminal apparatus 1or the like by means of the mail transmission/reception function 43.Furthermore, the teleconference terminal apparatus 1 can performcollaboration work in a group of users in conjunction with otherteleconference terminal apparatus 1 having the groupware clientfunction, via the groupware server 4, by means of the groupware clientfunction 42. For example, an email can be transmitted to eachteleconference terminal apparatus 1 or other terminal apparatus tonotify of teleconference via the groupware server 4 to reserve theteleconference, or detailed preparation associated with theteleconference can be performed using the web browser function 41.

(Screen Display of Teleconference Terminal Apparatus 1)

The teleconference terminal apparatus 1 configured as described abovedisplays, as shown in FIG. 2, a participant display section 61 whichdisplays a motion image of a participant to a teleconference, and aresource display section 62 which displays resources such as data andschedules used in the conference. The number of participant displaysections 61 corresponds to the number of participants. The participantdisplay section 61 displays a high-quality motion image of a speakingparticipant on a screen, and at the same time displays a low-qualitymotion image of a participant, who is not speaking, on the screen.

It should be noted in the present embodiment that the participantdisplay section 61 displaying a speaking participant is configured so asto display a high-quality image. However, examples of the configurationare not limited to this example, thus, for example, the image quality ofthe participant display section 61 may be enhanced and the participantdisplay section 61 itself may be enlarged, or a display position on theparticipant display section 61 may be changed to a center or the like.

(Operations of Teleconference System and Teleconference TerminalApparatus 1)

With the above configuration, an operation of the teleconference systemis explained, and an operation of the teleconference terminal apparatus1 is explained with reference to the communication image processingroutine shown in FIG. 3.

In the groupware server 4 a schedule of a conference is managed. When itis determined that the conference is carried out on predetermined timeand date, a mail for notifying of the conference is transmitted from thegroupware server 4 to the teleconference terminal apparatus 1 having thegroupware client function or other terminal apparatus. A person whoreceives the notification of the conference sets the image-capturingdevice 11, microphone 14, and the like of the teleconference terminalapparatus 1 to an operating state, reads information required in theconference by means of the web browser function 41 of the userinformation processing section 17, as shown in FIG. 2, and causes theresource display section 62 to display the information, to prepare forthe conference. Then, by operating the operation section 52, the personreports to the groupware server 4 that preparation for the conference iscompleted.

When the preparation for the conference is completed, in the imageprocessing section 13, an image signal which is obtained by capturing animage of a participant by means of the image-capturing device 11 isloaded to the A/D converter 21, converted into a digital signal, storedtemporarily in the transmission frame memory 22, and thereaftercompressed at a compression ratio based on a voice detection signal inthe encoder section 24 of the image codec section 23. The compressedimage signal is outputted from the image processing section 13 to theinterface section 54, and is transmitted to other teleconferenceterminal apparatus 1 via the MCU 3 through the communications network 2,or transmitted directly to other teleconference terminal apparatus 1 viathe communications network 2. Further, the image signal which isreceived via the communications network 2 is decoded (unpacked) by thedecoder section 25, temporarily stored in the reception frame memory 27,changed to an analog signal by the D/A converter 26, and then outputtedto the display device 12. It should be noted that an own image signal isalso outputted to the display device 12 by the reception frame memory 27or an unshown display circuit. Accordingly, as shown in FIG. 2, motionimages of, for example, four participants are displayed on theparticipant display section 61 of the display device 12.

Further, in the voice processing section 16, a voice signal which isobtained by collecting sounds of participants by means of the microphone14 is loaded to the A/D converter 31, converted into a digital signal,and temporarily stored in the transmission frame memory 32. The signalis then outputted from the transmission frame memory 32 to the computingsection 51, outputted to the voice codec section 33, and compressed at apredetermined compression ratio by the encoder section 34 of the voicecodec section 33. Thereafter, the compressed voice signal is outputtedfrom the voice processing section 16 to the interface section 54, andtransmitted to other teleconference terminal apparatus 1 via the MCU 3through the communications network 2, or transmitted directly to otherteleconference terminal apparatus 1 via the communications network 2.The voice signal received via the communications network 2 is decoded(unpacked) by the decoder section 35, temporarily stored in thereception frame memory 37, converted into an analog signal by the D/Aconverter 36, and then outputted to the speaker 15. Accordingly, asshown in FIG. 2, a speech of a participant is outputted as a voice fromthe speaker 15 of the teleconference terminal apparatus 1.

When the image signal and the voice signal are subjected to variousprocesses in the manners described above, the communication imageprocessing routine shown in FIG. 3 is executed in the computing section51. Specifically, first, a voice signal is loaded from the transmissionframe memory 32 (S1), and the level of the voice is computed on thebasis of the voice signal (S2). Then, it is determined whether the levelis a predetermined value or more (S3). If the level is a predeterminedvalue or more (S3, YES), a voice detection signal is outputted to theimage codec section 23, whereby an image codec is set to alow-compression ratio (high-resolution image quality). Accordingly, thedata amount of an image signal outputted to the communications network 2becomes large, but a high-quality motion image of the participantdisplay section 61 of a notable speaking person is displayed in all ofthe teleconference terminal apparatuses 1 (S4). Then, a resolution flagis set to “1” (S5) to indicate that the quality of the image is high,counting of the time period elapsed since the image quality is changedto high quality is started (S6), and thereafter the routing is ended.

When the level is not the predetermined value or more (S3, NO), it isdetermined whether the resolution flag indicating the condition of theimage quality at the present moment is “1” or not (S7). If theresolution flag is not “1” (S7, NO), it is determined that the image isof low-resolution quality, i.e. the image signal is compressed at a highcompression ratio, and the process is executed again starting from S1.On the other hand, when the resolution flag indicating high quality is“1” (S7, YES), it is determined whether a predetermined time period haselapsed since the image quality is changed to high quality (S8). If apredetermined time period has not yet elapsed (S8, NO), the process isexecuted again starting from S1. Accordingly, even if a speech isinterrupted temporarily, the high quality is maintained during thepredetermined time period, whereby distortion of the image can bereduced.

When the predetermined time period has elapsed (S8, YES), outputting ofthe voice detection signal to the image codec section 23 is stopped,whereby the image codec is set to a high compression ratio(low-resolution image quality). Accordingly, the data amount of theimage signal outputted to the communications network 2 becomes small andthe traffic in the communications network 2 can be reduced (S9).Thereafter, the resolution flag is set to “0” to indicate that the imagequality is low (S10), and then the routine is ended.

(Summary of the Present Embodiment)

As described above, the teleconference terminal apparatus 1 of thepresent embodiment is for carrying out a teleconference bytransmitting/receiving an image signal and voice signal via thecommunications network 2, and comprises: the image-capturing device(image-capturing device 11 and the like) which generates an image signalby capturing an image; the image output processing section (imageprocessing section 13 and the like) which converts the image signal to asignal mode corresponding to the communications network 2 and outputsthe converted signal; the microphone (microphone 14 and the like) whichperforms detection of a voice along with the image capturing, andthereby generates a voice signal corresponding to the level of thevoice; the voice output processing section (voice processing section 16and the like) which converts the voice signal to a signal modecorresponding to the communications network 2 and outputs the convertedsignal; and the image output processing control section (computingsection 51 and the like) which increases or reduces the amount of dataof the image signal outputted from the image output processing section,on the basis of the level of the voice signal.

According to the above configuration, since the amount of data of theimage signal transmitted to the communications network 2 can beincreased or reduced on the basis of the level of the voice signal, thevoice signal can be used as a switch for switching the image quality orscreen update interval. For example, an image of particular importanceis detected by means of the level of the voice signal in ateleconference, and the amount of data of an image signal of the imageis increased so as to set the quality of the image to high quality.Accordingly, compared to the conventional case in which all imagesignals of the same data amount are transmitted to the communicationsnetwork 2, contents of particular importance can be checked, throughgood image quality and the like, while preventing the traffic in thecommunications network 2 from expanding.

Moreover, the image output processing section of the present embodimenthas the image codec section 23 which compresses the image signal, andthe image output processing control section is configured so as toincrease or reduce the amount of data by changing the compression ratioof the image signal in the image codec section. It should be noted thatthe present embodiment describes change of compression ratio by usingtwo types of image qualities, i.e. high quality and low quality, butexamples are not limited to this embodiment, and thus there may be threeor more types of image quality, and the compression ratio may be changedlinearly so that high quality is obtained in proportion to the level.

According to the above configuration, when the image is a motion image,the quality of the motion image varies when the motion image is replayedand displayed. However, the movement of the motion image can be madeuniform among all of the teleconference terminal apparatuses 1, thus theabove configuration can be made excellent in terms of real-timeproperties.

Furthermore, the teleconference system of the present embodimentcomprises a plurality of teleconference terminal apparatuses 1 havingthe above configuration, and the communications network 2 which connectsthe teleconference terminal apparatuses 1 so that data can becommunicated. According to this configuration, for example, an image ofparticular importance is detected by means of the level of a voicesignal in a teleconference, and the amount of data of the image signalof the image is increased so as to obtain high quality, whereby contentsof particular importance can be checked, through good image quality andthe like, while preventing the traffic in the communications network 2from expanding.

Moreover, the teleconference communication method of the presentembodiment is a method for carrying out a teleconference bytransmitting/receiving an image signal and voice signal via thecommunications network 2, wherein when an image signal generated bycapturing an image is converted to a signal mode corresponding to thecommunications network 2 and outputted, the amount of data of the imagesignal is increased or reduced on the basis of the level of a voicewhich is generated by detecting voice when the image capturing isperformed. According to this configuration, since the amount of data ofthe image signal transmitted to the communications network 2 can beincreased or reduced on the basis of the level of the voice signal, thevoice signal can be used as a switch for switching the image quality orscreen update interval. Therefore, contents of particular importance canbe checked, through good image quality and the like, while preventingthe traffic in the communications network 2 from expanding.

(Modification of the Present Embodiment)

In the present embodiment, the compression ratio of the image codec inthe image codec section 23 is changed, and thereby the amount of data ofthe image signal is increased or reduced, but examples are not limitedto this example. Specifically, as shown in FIG. 4, a gate 71 (gate)capable of stopping transmission of image signals is provided on a frontstage of the encoder section 24, and the computing section 51 (imageoutput processing control section) stops transmission of image signalsin the gate 71 at predetermined intervals, whereby the data amount maybe increased or reduced. According to this configuration, when the imageis a motion image, fluctuation in movement of the motion image occursamong the all teleconference terminal apparatuses 1, but since the imagequality of each teleconference terminal apparatus 1 can be made uniform,good visibility can be obtained. It should be noted that the gate 71 maybe provided on a front stage of the transmission frame memory 22 or on afront stage of the A/D converter 21. In addition, the teleconferenceterminal apparatus 1 may change the data amount of the image signal atboth compression ratios of the gate 71 and the image codec.

The above has described the embodiment of the present invention, but theabove explanation is merely a concrete example and is not toparticularly limit the present invention, thus the design of thespecific configuration and the like can be changed accordingly. Itshould be noted that the operations and effects described in theembodiment merely details the most preferred operations and effectsproduced from the present invention, thus the operations and effectsaccording to the present invention are not limited to the ones describedin the embodiment of the present invention.

1. A teleconference terminal apparatus for carrying out a teleconferenceby transmitting and receiving an image signal and voice signal via acommunications network, the teleconference terminal apparatuscomprising: an image-capturing device which generates an image signal bycapturing an image; an image output processing unit which converts theimage signal to a signal mode corresponding to the communicationsnetwork and which outputs the converted signal; a microphone whichperforms detection of a voice along with the image capturing, andthereby generates a voice signal corresponding to level of the voice; avoice output processing unit which converts the voice signal to a signalmode corresponding to the communications network and outputs theconverted signal; and an image output processing control unit whichincreases or reduces the amount of data of the image signal outputtedfrom the image output processing unit, on a basis of the level of thevoice signal.
 2. The teleconference terminal apparatus according toclaim 1, wherein the image output processing unit comprises an imagecodec unit which compresses the image signal, and the image outputprocessing control unit increases or reduces the data amount by changingthe compression ratio of the image signal in the image codec unit. 3.The teleconference terminal apparatus according to claim 2, wherein theimage output processing control unit is connected to at least an encoderunit of the image codec unit and a transmission frame memory of thevoice output processing unit, which loads a voice signal transmittedfrom the transmission frame memory, and which transmits, to the encoderunit, a command signal associated with increase or reduction of the dataamount of the image signal, on a basis of level information of theloaded voice signal.
 4. The teleconference terminal apparatus accordingto claim 3, wherein the image output processing control unit determineswhether the level information of the loaded voice signal, which isinputted, is a predetermined value or more, and wherein the commandsignal is transmitted to the encoder unit such that, if the levelinformation is at least the predetermined value as a result of thedetermination, the image signal is obtained as low-compression ratiodata, and, if the level information is less than the predetermined valueas a result of the determination, the image signal is obtained ashigh-compression ratio data.
 5. The teleconference terminal apparatusaccording to claim 4, wherein, in a case in which the level informationis less than the predetermined value as a result of the determination,when a current image is set so that the low-compression ratio data areobtained, the determination is repeated until a predetermined timeperiod elapses, and as a result the command signal is transmitted to theencoder unit so that the image signal is obtained as high-compressionratio data, on the condition that it is still determined that the levelinformation is less than the predetermined value.
 6. The teleconferenceterminal apparatus according to claim 1, wherein the image outputprocessing unit comprises a gate which stops transmission of imagesignals, and the image output processing control unit increases orreduces the data amount by stopping transmission of image signals in thegate at fixed intervals.
 7. A teleconference system comprising: aplurality of the teleconference terminal apparatuses according to claim1; and a communications network which connects the teleconferenceterminal apparatuses to communicate data.
 8. A teleconferencecommunication method for carrying out a teleconference by transmittingand receiving an image signal and voice signal via a communicationsnetwork, wherein when an image signal generated by capturing an image isconverted to a signal mode corresponding to the communications networkand outputted, the amount of data of the image signal is increased orreduced on the basis of the level of a voice which is generated bydetecting voice when the image capturing is performed.